Apparatus for burning liquid fuel



P 19, 1939- c. B. HILLHOUSE 73,

APPARATUS FOR BURNING LIQUID FUEL Filed Nov. 1, 19:54

.. g J J 45 (Mesa/M500 8 44 Patented Sept. 19, 1939 APPARATUS FOR BURNING LIQUID FUEL Charles B. Hillhouse, New York, N. Y., assignor to Sylvia. Remsen Hillhouse, New York, N. Y.

Application November 1, 1934, Serial No. 751,044

6 Claims.

My invention relates to an apparatus for burning liquid fuel and more particularly to an apparatus for burning hydrocarbon oil of either heavy or light fuel type.

The main object of my invention is to heat and gasify the oil, prior to its final combustion, in a manner to avoid any cracking of the oil and to maintain the gas at a uniform temperature above the dew point.

Another object is to provide an apparatus wherein a current or cycle of hot gasified oil is maintained in the burner apparatus in excess of requirements of the burner flame and continuously adding to this current of gas sufficient new gas to maintain a desired volume of gas and imparting, at the same time, additional heat to the current of gas to maintain a desired temperature thereof.

The apparatus includes also means for gasifying the oil by indirect contact therewith of a vapor of substantially constant temperature, which vapor is supplied from a body of liquid maintained in heated condition normally by burning a portion of the gas produced by the apparatus or other heating agent.

This application is related to my co-pending application, Serial No. 679,767, for Method of burning oil as gas, filed July 10, 1933.

According to the present improved apparatus,

a supply of fuel oil is subjected continuously through heat exchange relation to a source of heat in the form of a hot vapor derived from a body of liquid, preferably mercury. I find that mercury vapor at the boiling point of mercury is particularly suitable because its temperature at substantially atmospheric pressure is about 670 R, which is below the cracking temperature of the fuel oil to be gasified. This oil is gasified after having been admitted to a gas circulating conduit of an endless type. The capacity of this conduit or system is sufficient to maintain the volume in the gas cycle at about twenty times that of the new oil gasified. The formed gas is maintained in circulation by means of a blower fan and, at one point, is caused to contact a surface which is maintained heated by means of the mercury vapor which serves also to heat the oil-gas and the oil sprayed into it. By varying the pressure of the mercury, the vapors thereof may be heated up to about 825 F., corresponding to fifteen pounds pressure above atmospheric pressure. The formed gas in this gas cycle conduit is admitted to the main gas burner jets at a desired point. As the gas is consumed at the burners, new additions of oil are proportionately supplied to be gasified at a suitable point in the gas cycle.

A portion of the made gas isled off from the closed cycle and fed to an auxiliary burner which serves to heat the mercury chamber.

In this, manner, heat is constantly supplied to the circulating gas including the oil which is being gasified, and from a source of heat comprising the hot mercury vapor.

Figure 1 of the drawing, wherein various parts of the apparatus are shown in section and others in schematic form, discloses one type of apparatus.

Figure 2 is a part View in section of a modification.

a second plate or flange 4.

The flanges 2 and 4 may be secured. together by bolts passing through registering holes 5.

.A mercury retort 6 is also secured axially within the plate 4 and is welded thereto.

A pair of spaced coaxially arranged mercury vapor or heat exchange tubes 7 and 8 are secured at their lower ends to the retort 6. The tube 1 terminates at its lower end in a thickened portion 9 which serves to space tubes 7 and 8. A similar spacing lug or flange is provided at H3 at the upper end of the tube 1.

A spiral rib or baffle l I is formed on the outer face of the tube 1 and this rib closely engages the inner wall of the tube 8.

A pair of smaller, open ended,

tubes l2 and [3 are secured within the tube 1 and retort 6 by means of a lower plug it and an upper plug l5. A terminal cap or casing i6 is secured to the upper end of tube 8 and a filler plug I! is provided to permit mercury to be poured into this cap, and a hole H8 in plug I5 permits passage of mercury into the tube 7,

thence through tube l3 to retort 6.

The tube 1 has a pair of ports I?! at the lower end and a port 20 at its upper end. Mercury vapor may pass up through tube l2, out through port 20, thence spirally downwardly between tubes 7 and 8, inwardly through the ports through tube l3 to the retort 6.

l9 and down To provide a more efficient heating means, a series of mercury retaining tubes 6' may be extended from casing 6 as shown in Fig. 3.

The gas cycle or circulatory systems is indicated by means of double arrows 21.

The casing I is provided with an inlet 28 and an outlet 29 positioned, respectively, adjacent the lower and upper ends of the casing l. A motor 3!] drives a fan 3| to force gas from inlet conduit 28 arranged, preferably, at a tangent to the walls and around the space between casing l and the hot tube 8. This reheated gas leaves by the outlet 29 and flows up through conduit 32 transversely through a conduit 33 suitably insulated as at 33 to the main burner jets 34 and back to inlet 28. Air, preferably preheated, is supplied to jets 34 from air conduit 35 controlled by a valve 36. A valve 3'! may be used to control flow of gas in the conduit 33.

In order to initially heat the mercury, a pilot burner 42 is provided and supplied with a suitable fuel, preferably a fixed gas, from conduit 43 and air from conduit 44, and these conduits are provided with valves 45 and 46, respectively. After the burner device has operated to provide a proper gas circulation cycle, the burner 42 is shut 01f and gas from the outlet 29 is passed through a conduit 47 and valve 48 to a burner 49. Gases of combustion within the casing 3 pass out through stack 50 and a valve 5|. If desired, in starting up, hot stack gases produced by the pilot burner 42 may be admitted from the stack 50 through a conduit 52 and valve 53 into conduit 33 in order to produce a preliminary heating of the gas pipe system including the casing'l and wall of tube 8. Gases of combustion from the jets 34 are collected by a hood 54 and are conducted through a pipe 55 to the stack 50.

In order to maintain a constant and new supply of oil gas in the gas cycle, I inject fuel oil at a temperature of above 212 F., but below vaporizing temperature, from a jet spray 56 into the return gas conduit from the burners 34 at a point behind the fan 3|. This oil is fed by a conduit 5'! from an oil heater 58 which, in turn, is supplied from an oil supply inlet conduit 59. The oil in heater 58 is maintained at a temperature of upwards of 212 by means of heat supplied from boiling water or other fluid in a boiler 66, or other means of heating, as a supply of heated air. Water is fed to the boiler 60 from inlet conduit 6| and steam from boiler 60 may escape from an outlet 62. By varying the pressure of the steam, I can raise its temperature readily to 500 F. or above, which may be of advantage. The water in boiler 60 may be heated by means of flue gas from fiue 58. A damper 63 causes a portion of the flue gas to pass out through an outlet 64 to surround the boiler 60 and thence through a passage 65 back to the stack. In starting up, however, the water in the boiler may be heated in any well known manner, for example, by a burner or electrically, or by gases from flue 50 produced by the starting burner 42. A valve 62' may be arranged in steam outlet 62 if desired to control pressure and temperature in boiler 60.

In Fig. 2, is shown a modification wherein an electrical heating means in the form of electric heating coils 66 are provided on the inner faces of the gas inlet 28 to casing I, as well as on the inner wall of the casing l itself. The coils 66 may be maintained at a temperature of upwards of 600 F. When such heating coils are used, they are energized when it is desired to heat up the residual gas, the walls of conduit 28 and casing l in starting the gas cycle in the oil burner.

In order to maintain the temperature of the mercury vapor constant, I provide a thermostat 61 connected by conductors 68 through a battery 69 to an electrically operated valve 10 which controls the gas feed from conduit 41 to burner 49. To provide additional gas control, a pressure gauge H is mounted on casing 16. Conductors 12 and 13 from pointer 14 and contact 15, respectively, are connected in parallel with conductors 68.

In operation, the pilot flame 42 is lighted and all or a portion of the gases of combustion produced thereby are drawn from conduit 52 through the gas cycle conduits 33, 28, 29 and 32, by fan 3|. No excess air for combustion should be used at this stage of operation. At the same time, the electric heating coils 66 are energized to heat the gas cycle pipes. As soon as the gases of combustion and pipes heated thereby reach a temperature of about 650 F., further gases of combustion should be shut off at valve 53. When the mercury vapor is heated high enough to maintain the cycle of gases of combustion at the desired temperature, or a temperature of about 850 F. for the mercury, the heated oil from heater 58 is injected at nozzle 56 slowly in highly atomized form and preferably at a temperature of about 300 F. This oil spray is gasified at once by mixing into the oil gas cycle and by contact with the hot wall 8, but the greater part of the heat required for the gasification of the oil additions will be furnished by the sensible heat contained in the gases of the cycle and only a smaller portion of heat by contact with the heated walls. At this stage, made gas can be admitted slowly to main burner 49 through the valve 48. increase, the pilot burner 42 can be shut down. When shutting off the main burner, the pilot burner should be started again and suflicient gases of combustion therefrom passed through the cycle conduits to drive out any condensed oil vapor and leave only gases of combustion in these pipes. At this stage, also, no excess air for combustion should be supplied. In case the cycle conduits contain gases of combustion from a previous run, they may be heated up again by the coils 66, thereby avoiding use of the pilot burner 42. It is important to not permit anything to enter the gas cycle conduits except pure gases of combustion without excess air, into which gases, the atomized oil is initially sprayed.

While I have shown and described a preferred form of my invention, it is to be understood that various modifications are contemplated such as will be embraced within the scope of the appended claims.

What I claim is:

1. An apparatus for gasifying oil and burning same'comprising a retort adapted. to contain a body of liquid, means for heating the retort to vaporize the liquid, a heat exchange wall, a second wall spaced from said heat exchange wall and forming a chamber between said walls, means for passing the vapor from the liquid over one face of the wall, means for maintaining a stream of atomized oil within said chamber in contact with the heat exchange wall and through said chamber to gasify the oil, a conduit connected at opposite ends with said chamber, a burner connected to said conduit, means to supply air to the burner and means for maintaining a flow of made gas through the conduit and chamber and over said opposite wall face.

2. In an apparatus as set forth in claim 1, means for condensing the vapor from the liquid As the main flame at 49 is made to r and passing the condensed vapor into the body of liquid.

3. In an apparatus as set forth in claim 1, a burner for heating the retort, and means for conducting a portion of the made gas to said burner.

4. An apparatus for gasifying oil and burning same comprising three spaced concentric walls providing an inner chamber and an outer chamber surrounding the inner chamber, a retort in communication with the inner chamber, a quantity of liquid in said retort, means for heating said liquid, means for conducting the vapor from the heated liquid to the inner' chamber to heat the wall thereof, means for maintaining a stream of atomized oil in the outer chamber to contact the heated wall to gasify the oil, a burner, means to supply air to the burner, a conduit connecting the burner to the outer chamber, a return conduit connecting the outer chamber to the burner, and means for forcing unburned gas from the burner back to said outer chamber.

5. In an apparatus as set forth in claim 4, electrically heated means for heating the portions of unburned gas during the passage thereof through said conduits.

6. In an apparatus as set forth in claim 4, means for maintaining constant the temperature of the vapor from the heated liquid.

CHARLES B. HILLI-IOUSE. 

